NASA Considers Nuclear Option to Deflect ‘City-Killer’ Asteroid 2024 YR4

NASA has intensified its study of nuclear disruption strategies to avert a potential lunar impact by asteroid 2024 YR4, a 60-metre object projected to pass near the Moon in 2032. Although the asteroid poses no direct threat to Earth, the risk of a lunar collision has prompted detailed mission assessments aimed at preventing secondary space hazards.

Renewed Focus on Planetary Defence

The asteroid, discovered in December 2024, follows an orbit that occasionally intersects the Earth–Moon system. Recent data suggest a 3.8% probability of lunar impact, sufficient to trigger precautionary planning. NASA and international research teams are evaluating mission windows from late 2029 to late 2031 to develop a response plan that could safeguard satellites and human spaceflight assets from potential debris clouds.

Kinetic vs Nuclear Deflection Approaches

Traditional kinetic impactors, designed to alter an asteroid’s trajectory through momentum transfer, are deemed inadequate for an object of this size and mass. Studies from arXiv and NASA’s Jet Propulsion Laboratory indicate that the energy required to redirect 2024 YR4 exceeds the capability of existing spacecraft. Nuclear intervention, by contrast, offers a scalable and powerful means of imparting sufficient impulse through controlled detonation.

Physics of Nuclear Standoff Detonation

In the proposed nuclear standoff model, an explosive device would detonate at a calculated height above the asteroid’s surface. The radiation from the blast would vaporise part of the asteroid’s exterior, generating thrust to alter its velocity. This method avoids the need for physical anchoring and allows fine control over energy output and fragmentation risk. Researchers describe it as an effective rapid-response solution when conventional deflection timelines are too short.

Exam Oriented Facts

• Asteroid 2024 YR4 measures approximately 60 ± 7 metres across.
• The nuclear standoff technique involves detonation above the asteroid’s surface, not on impact.
• NASA’s potential mission windows span from 2029 to 2031.
• A lunar impact could temporarily increase micrometeoroid flux by up to 1,000 times.

Policy and Engineering Challenges Ahead

Executing a nuclear mitigation mission would require international coordination and compliance with space treaties restricting nuclear use in orbit. NASA’s Planetary Defense Strategy recognises such actions as last-resort measures, contingent on verified threats. Advanced propulsion systems and radiation-hardened spacecraft currently under development could support such missions if authorised. The case of 2024 YR4 thus represents both a technological and policy test for future planetary defence operations.